Treatment of hydrodemolition water
Treatment of water used for hydrodemolition.
Water is a vital good which must be safeguarded at any cost and is essential in all fields, from civilian to industrial. In construction it is necessary for all concrete mixes, for washing and, especially in the last half-century, in hydrodemolition. The latter process can be briefly described as the removal of any material by the impact at high velocity of a water jet on the surface being treated.
In the construction industry hydrodemolition technology is used mainly for the removal of damaged concrete, of plaster and paint, and for the roughing treatment necessary for the adhesion of new material.
The hydrodemolition process requires the pumping of water from natural sources such as rivers, streams, ponds, etc. or the use of water from aqueducts. The water is then turned into a high-pressure stream by a piston or plunger pump and delivered to the nozzle.
After impacting the material and the resulting removal of part of it, water, as effect of gravity, falls and mixes with concrete, inert material, chemicals and dust.
Part of these sediments have a natural origin, while others can be harmful and, apart from creating visible white streams in the nearby water basins, they can pollute downstream water sources.
JetBlast strives to minimise environmental impact, to make waterjetting sustainable and respect the principles of climate-friendliness to design, build and integrate water depuration systems.
These systems not only filter solid particles from the water but also use chemical and physical sedimentation before releasing it in the environment or re-using it in a closed loop, using only the minimum necessary quantity of water to compensate for losses from nebulisation of the high-pressure jets.
Filtering systems are designed in function of the required flowrate. They can be placed on the worksites and later removed or built in-situ using the morphology of the terrain, after having placed appropriate barriers to prevent any seepage in the soil. In the case of works on the upper surface of the concrete slab of a bridge it is easy to funnel the water used for hydrodemolition toward the depuration system. In case of waterjetting works on the lower surface it is instead necessary to dig recovery channels and feed the depuration system with a pow-pressure pump.
